1. Field of the Invention
This invention relates to liquid dispensers, and in particular to devices for dispensing cleaning and freshening liquids from under the rim of a toilet bowl.
2. Description of the Related Art
Toilet bowls require care to prevent the buildup of unsightly deposits, to reduce odors and to prevent bacteria growth. Traditionally, toilet bowls have been cleaned, deodorized and disinfected by manual scrubbing with a liquid or powdered cleaning and sanitizing agent. This task has required manual labor to keep the toilet bowl clean.
In order to eliminate the manual scrubbing, various automatic cleaning toilet bowl cleaning products have been proposed. One type of product comprises a solid block or solid particles of a cleansing and freshening substance that is suspended from the rim of a toilet bowl in a container that is placed in the path of the flushing water. U.S. Pat. Nos. 2,214,798 and 3,529,309 and U.S. patent application Publication Ser. No. U.S. 2002/0083514 show examples of this type of toilet bowl cleaning system. Typically, a portion of the solid block is dissolved in the flush water with each flush, and the flush water having dissolved product is dispensed into the toilet bowl for cleaning the bowl. These solid block toilet cleaning systems have certain disadvantages such as a short lifetime and a decline in the amount of cleaning and deodorizing agents released into the toilet bowl as the solid block deteriorates.
Other automatic toilet bowl cleaning systems use a liquid cleaning agent that is dispensed into a toilet bowl. For example, European Patent Application Nos. EP 0538957 and EP 0785315, U.S. Pat. Nos. 6,178,564, 6,230,334, 6,389,610, 6,412,120, 6,434,758, and 6,519,783, PCT International Publication Nos. WO 99/66139 and WO 99/66140, and U.S. patent application Publication Ser. No. 2002/0116751 all disclose cleansing and/or freshening units capable of being suspended from the rim of a toilet bowl for the purpose of introducing liquid active substances from a bottle into the flushing water with each flush. Typically, the liquid active substances may include one of more of the following: surfactants (such as a mixture of an anionic surfactant and a nonionic surfactant), solvents, sequesterants, pH controllers, thickeners, preservatives, fragrances, and dyes.
While these under the toilet rim liquid dispensing toilet bowl cleaning systems provide an improved alternative to the solid block toilet cleaning systems described above, it may be difficult to incorporate certain toilet bowl cleaning actives, such as bleaches and various hypochlorites, into the liquid active substance. In this regard, bleaches and hypochlorites may affect properties of the components of the liquid active substance. For example, bleaches and hypochlorites will typically fade the color of a dye and destroy a fragrance upon extended contact. Also, certain incompatible cleaning actives may not be stable when mixed and through the resulting chemical interaction, the efficacy of the individual cleaning actives may be decreased. For instance, the efficacy of certain surfactants may be decreased by bleaches and hypochlorites. These limitations in liquid dispensing cleaning systems have prevented the optimization of toilet bowl cleaning active substances in one liquid formulation. In particular, the inability to incorporate bleaches and hypochlorites into a liquid active substance is especially detrimental as bleaches and hypochlorites are particularly effective in destroying bacteria and preventing biofilm formation.
The problems associated with incompatible cleaning actives can be addressed through the use of an automatic under the toilet rim cleaning system having separate compartments for two liquids or for a liquid and a solid. For example, U.S. patent application Publication Ser. No. 2002/0148036A1 (also WO 02/064898A1) discloses a liquid dispensing unit for a toilet bowl that includes a first container containing a first, liquid formulation, a second container containing a second formulation, which may be a solid tablet or a liquid. The liquid from container flows onto a delivery surface from where it is washed into the toilet bowl by the flush water. Some flush water also washes over the second formulation to take components into solution and deliver them into the toilet bowl through an aperture. The constituents of the two formulations are thus kept separate until they enter the toilet bowl. WO 02/40792A1 describes an under the toilet rim dispenser having a reservoir with two liquid compartments and a third compartment for a solid cleansing block. Outlets from the two liquid compartments deliver the liquids to a porous mass where flush water mixes with the liquids and enters the toilet bowl. Flush water also enters the third compartment and dissolves a portion of the solid block before entering the toilet bowl. WO 02/40791A1 and WO 02/40787A1 also describe under the toilet rim dispensers having a reservoir with two liquid compartments.
While these two cleaner automatic under the toilet rim cleaning devices may address the problems associated with incompatible cleaning actives, these devices can be quite bulky and as a result, these devices spoil the look of the toilet. What is needed therefore is an improved toilet rim mounted device for dispensing two separate liquids wherein the device is more completely hidden from view when the device is installed on a toilet rim.